W 250 Pickup L6-359 5.9L DSL (1989)
Oil Filter: Description and Operation
Lubrication For The Turbocharger
OIL FILTER
After the oil Is cooled, it flows through the full flow oil filter. From the filter oil flows to the turbocharger and engine.
OIL FILTER BYPASS VALVE
The oil cooler cover contains a bypass valve (5) that will let the oil flow bypass a plugged filter. The valve is designed to open when the pressure
drop across the filter is more than 138 kPa [20 PSI], as with a plugged filter, and lets the oil continue on through the engine. When a filter
becomes plugged, an oil pressure decrease of 60 kPa [10 PSI] or less from the normal operating pressure can be observed on the vehicle oil
pressure gauge.
